Outboard motor



E. c. Klr-:KHAEFER 2,718,866

OUTBOARD MOTOR Sept. 27, 1955 5 Sheets-Sheet l Filed OGL 8 1951 INVENTOR.

Sept 27, 1955 E. C. KIEKHAEFER OUTBOARD MOTOR 3 Sheets-Sheet 2 Filed Oct. 8 1951 l I l I 1 L l l f I l I Sept, 27, 1955 E, c. KIEKHAEFER OUTBOARD MOTOR I5 Sheets-Sheet 3 Filed OCT.. 8 1951 United States Patent O OUTBOARD MOTOR Elmer C. Kiekhaefer, Cedarburg, Wis.

Application October 8, 1951, Serial No. 250,262

9 Claims. (Cl. 11S-18) This invention relates to outboard motors and particularly to the type of motor which as conventionally constructed includes a hollow, vertical drive shaft housing supporting at its upper end the power head including the engine and having a propeller unit fixed thereto at its lower end. The invention contemplates a modication of the conventional construction which provides at once easier operation of the starter rope, a weedless and more efficient underwater unit, more trouble-free carburetion, a more securely supported motor, and better balance of the motor for improved riding in the boat.

An object of the invention is to locate the engine of the motor unit closer and more convenient to the operators position in the boat.

Another object is to locate the weight of the motor unit closer to the center of balance of the boat for better flotation of the boat at rest and greater stability in motion.

Another object is to carry the motor unit so that its weight is resiliently supported by the boat directly above the transom and with the axis of vibration of the motor unit disposed parallel to the transom.

Another object is to dispose the engine of the motor to allow eflicient draining of the engine crankcase and carburetor mixing passage while maintaining the carburetor in its normal position respecting the engine and immediate to the operator within the boat.

Another object is to provide a starter cord which unwinds toward the operator and somewhat downwardly into the boat cockpit for easier pulling and without tilt ingthe motor.

Another object is to increase the eiciency of the gears of the underwater structure of the motor unit providing longer gear life and to dispose the lower unit angularly so that weeds are not picked up and carried by the unit.

These and other objects and advantages will be more fully set forth in the following description of a preferred embodiment of the invention as illustrated in the accompanying drawings.

- In the drawings: i Figure 1 is a side view of the upper part of the motor unit with portions thereof broken away and sectioned;

Fig. 2 is an enlarged detail View taken through a part of the motor unit normal to its steering axis and showing the upper mounting of the motor for steering;

Fig. 3 is a side view of the lower part of the motor unit with portions thereof broken away and sectioned;

Fig. 4 is a sectional view taken on line 4 4 of Fig. 3 showing the driven gear in front elevation;

Fig. 5 is vertical transverse section showing the position of the drive gear forwardly of the driven gear;

Fig. 6 is a sectional view taken on line 6 6 of Fig. 3; and

A Fig.`7 is a sectional view taken on line 7--7 of Fig. 3. i The motor unit 1 is supported by the clamp bracket 2 which comprises spaced clamps, including the clamp 3 shown, and which are adapted to t over the upper edge of the transom 4 and on the centerline of the boat 5 partially shown in outline in Fig. 1. The cross-piece 6 f line.

Patented Sept. 27, 1955 rice and the bolt 7 extend transversely of bracket 2 and join the clamps to form a unitary, rigid structure. clamp 3 is fitted with a turn screw 8 by which the clamp is removably secured to transom 4.

The motor unit 1 includes the drive shaft housing 9 which carries the engine 10 at its upper end, the underwater structure 11 including the propeller 12 at its lower end.

The swivel bracket 13 carrying motor unit 1 is supported for tilting movement on the transverse bolt 7 and disposed between the individual clamps 3 of bracket 4. The lower part of bracket 13 normally rests against the Vcross-piece 6 on the outside of the boat which limits movement of motor unit 1 and bracket 13 in one direction on bolt 7. Limited movement of the motor unit on bolt 7 in the other direction is provided for to allow the underwater structure 11 to pass over submerged objects and to be raised out of water when not in use.

The swivel pin 14 is carried by bracket 13 to provide a steering axis parallel to the intersection of transom 4 and a vertical longitudinal plane respecting boat 5 and as shown in the drawings has a forward rake of approximately 20. That is, the axis of pin 14 defines a 20 upper angle with and forwardly of an intersecting vertical The lugs 15 formed integrally with housing 9 are fitted with resilient bushings 16 which latter are turnable on the upper and lower ends of swivel pin 14 to support motor unit 1 thereon.

The lower friction element 17 carried by bracket 13 is disposed beneath and frictionally engages the disc 18 carried by the sleeve 19 which latter is rotatably mounted on pin 14 independently of the motor unit. The upper friction elements 20 are located by plate 21 above and in engagement with disc 18. Plate 21 is secured to bracket 13 and is deflected by the bolt 22 and spring 23 to secure disc 18 between elements 17 and 20 against rotation subject tofsteering movement effected by means of the tiller 24.

Tiller 24 is preferably secured directly to disc 18, as shown, to turn the latter against the frictional resistance of elements 17 and 20 and to turn the motor unit on pin 14.

The springs 25 interposed between the ends 26 of disc 18 and housing 9 resiliently connect the same for rotation on pin 14, and resiliently secure the motor unit in a given steering position on the pin as maintained by elements 17 and 20.

Engine 10 of the motor unit is secured to housing 9 by the bolts 27 and includes the crankshaft 28 which is connected at its lower end to the drive shaft 29. Shafts 28 and 29 are in axial alignment and extend generally parallel to that of pin 14 so that torque vibration of the motor is allowed on pin 14 and can be absorbed by bushings 16 and springs 25. The vibration not absorbed by springs 25 is transmitted to transom 4 as a turning moment on the axis of pin 14. With pin 14 disposed parallel to the transom according to the invention, the turning moment is more fully absorbed by the transom without effecting the joints between the transom and other parts of boat 5. Full advantage of any resilience inherent in a transom of wood construction, for example, is realized by reason of the parallel relationship of the axis of vibration and the vertical centerline of the transom.

The crankcase 30 of engine 10 supporting the angularly disposed crankshaft 28 denes tilted corresponding crank chambers, including the chamber 31 shown. Each chamber is adapted to receive fuel and air from the mixing passage 32 of carburetor 33 and is provided with a drain passage similar to passage 34 which communicates with chamber 31. Passage 34 extends from the lower forward end of chamber 31 toward which the unvaporized fuel tends to collect and opens downwardly into housing 9 to allow discharge of the liquid fuel from the chamber Each while being suiciently restricted to prevent pressure losses therein. The engine cylinder block 35 is provided with cylinders including the lower cylinder 36 which carries for reciprocationt'ne piston 37 connected to crankshaft 28 .by the rod 38.

Carburetor 33 is secured to the forward side of crank case 3i) with suitable control means as shown projecting forwardly for manipulation by the operator within the boat and with passage 32 inclined so that the fuel mixture moves upwardly and the raw fuel which drops out of suspension in passage 32 similarly drains downwardly toward and from the lower open end of passage 32 and is thereafter channelled by the cowl d'7 out of the boat and dumped into the water in which the motor is operating.

The adequate draining of such excess [nel from both the carburetor mixing passage 32 and from the cranl: chambers 31 provides a more unito ily carbureted fuel delivery to the cylinders 36 for combustion. .Flooding of the engine with excess fuel is substantially prevented while complete and adequate lubrication of the crankshaft and connecting rod bearings is assured. Such uniformity of carbureted 'fuel provides improved engine operation at all speeds including idling speeds.

The chamber 39 formed in the side of. block is closed by plate 4@ on the side of the block and opens downwardly thereof into the upper open end of housing 9. The ports dll in block 3S provide for the exhaust of the cylinders into chamber 39 and into the upper end of drive shaft housing 9.

The ratchet wheel i2 fixed to the upper end of crankshaft 23 is adapted to be selectively engaged and rotated by the pawls 4Z to start the engine. Pawls 43 are carried by the reel d4 rotatably mounted on the pin d5. The starter cover plate 46 forms a part of the cowl a7 which is supported by and encloses engine l. the pin 45 in alignment with and adjacen o the upper end of crankshaft 28 and ratchet wheel 4Z. One end of the cord 48 wound on rcel i4 is secured thereto and the other end extends through opening i9 in cowl i7 and is secured to the handle Sil for pulling the cord. By pulling cord 48 the cord is unwound from and turns in one direction reel with pawls 43 which engage ratchet wheel 42 and turn crankshaft 28 of the engine. The spiral spring 5l is connected at opposite ends to plate d6 and reel 44 to turn the reel in t'ne opposite direction and rewind cord 43 on the reel.

In maintaining the alignment of pin 45, crankshaft 28 and drive shaft 29, cord i8 is necessarily wound and unwound in a tangential direction which extends forwardly and angularly downwardly into the boat cockpit from which position the operator pulls the cord. The angular-ity referred to and the direction of pull makes starting of the motor easier and with less tendency to tilting of the motor forwardly on the bolt 7.

The lower end of drive shaft housing 9 includes the shoe portion 52 extending rearwardly thereof and which opens rearwardly to discharge above and rearwardly of propeller 12 the exhaust from engine l@ and discharge from passage 3d. The tie bolts $3 secure the gear case 54 of the underwater structure ll to the lower end of housing 9 beneath the horizontal plate 55 formed integrally with housing 9 to extend over propeller 12 and prevent cavitation of the propeller.

Gear case 54 generally comprises a unitary, cast member which includes the strut 56 supporting the lower enlarged torpedo section 57, and the skeg 53 which projects downwardly from the torpedo section forwardly of propeller l2 to protect the latter against damage by submerged objects.

Strut 56 is of a narrow streamlined transverse section for minimum drag or resistance to movement through the water and has straight forward and rear leading edges 59 and 60, respectively, which extend generally parallel with the axis of shaft 29. The lower end of strut 56 is l?" e d6 carriesv faired to merge with the upper side of torpedo section S7. The outer dimension of torpedo section 57 is developed generally by rotation of an arc on the horizontal, longitudinal axis of the shaft 6l carried by the gear case and supporting propeller l2.

The forward end of section 57 merges as at 62 with leading edge 59 and the forward edge of skeg 58 so that an unobstructed forwardly inclined leading edge is provided for the underwater structure 11. Weeds and the like which may otherwise collect on the structure are thereby pushed dov/n by the water stream and released from beneath the skeg without fouling propeller 12 and interfering with the operation of the motor.

The rear end 63 of section 57 is truncated and the hub 67 of propeller 12 at the rear of section 57 is shaped to continue the streamlined dimensions to a terminal point rearwardly of the blades 64 of propeller 12.

The upper and lower bearings 66 and 67, respectively, are carried in strut 56 and support the lower portion of shaft 29 which extends through the strut and projects downwardly into the gear chamber 68 formed in torpedo section 57. rl`he bevel drive gear 69 is fixed to the lower end of shaft 29 within chamber 68 and immediately above shaft 61. The bevel driven gear 79 is fixed on shaft 61 rearwardly of gear 69 and meshes with gear 69. The roller bearing 7l within chamber 63 near the forward end 62 of section 57 is disposed forwardly of gear 69 and supports directly the forward end of shaft 61. Bearing 72 is mounted on the hub of gear 7) and is disposed to support the gear and the intermediate section of shaft 6l within chamber 68 rearwardly of gears 69 and 70.

The axes of shafts 29 and 6l and gears 69 and 70 intersect to eliminate lengthwise movement of the interr-.ieshing teeth of gears 69 and 70 and resultant frictional losses. The invention, in providing the forward angularity of shaft 29, as described, and the obtuse angularity of the axes of gears 69 and 70, also reduces the angle of incidence defined by the path of the teeth of the gears where the driven gear is disposed rearwardly of the drive gear as described. The reduced angle of the incidence provides an increased contact ratio of the teeth, greater gear capacity and longer gear life.

The angularity of drive gear 69 respecting gear 70 also allows for a more streamlined gear case 54, particularly respecting the torpedo section 57 thereof. After allowing the necessary clearances for gears 69 and 70 in chamber 63 and the necessary wall thicknesses of the gear case, the maximum required lateral dimensions of section S7 are determined by the diameters of both said gears. 'in front elevation, the diameter of the drive gear as carried by a vertical shaft projects transversely above the driven gear and adds to the frontal area required for the driven gear.

According to the present invention, the angular disposition of gear 69 as described places gear 69 directly in front of gear 7b as shown in Fig. 5 so that the frontal area and the maximum required lateral dimensions of torpedo section 57 are reduced substantially to the dimensional limitations required only for gear 70. A gear reduction ratio, as determined by the larger size of gear "lil and smaller size of gear 69, may be further employed while decreasing the size of the torpedo section or at least without substantial increase in size. Thus, the size of the gear case may be reduced accordingly to reduce the weight of the unit and further streamlined to allow greater speeds by reason of the reduced resistance to movement through the water.

Motor unit l as supported for steering movement on the inclined axis of pin 14 eifects tilting of the propeller which, in steering, provides an additional factor of Safety as defined and claimed in the present inventors copending application for Outboard Motor with Inclined Steering Axis, Serial No. 250,261, filed October 8, 1951.

The invention provides in the structural modifications of the motor unit as described, various features which allow for lighter and stronger construction of the boat as described and claimed in the present inventors copending application for Outboard Motor Boat, Serial No. 250,263, filed October 8, 1951, and provides therewith improved operation and serviceability of both the motor and motor unit.

By reason of the hollow construction of drive shaft housing .9 and the relatively small lower structure 11 which is disposed underwater, the weight of engine 2 and parts thereof, including cowl 47 and the starter assembly supported by the cowl, causes the center of gravity of the motor to be located as at 73 near the lower end of the engine and near the upper end of the motor unit. The center of gravity of the motor is accordingly located with respect to clamp bracket 2 so that the weight of the motor will be located in the transverse vertical plane 73a which extends between the upper and lower resilient bushings 16. The center of gravity of the motor unit as shown is also located directly above and supported by transom 4 when secured thereto as described and so that the weight of the motor exerts a force against transom 4 in the direction of the arrow 74 inwardly of the boat so that the transom is directly supported thereby.

The carrying handle 75 which is formed by an indentation 76 in the bottom of cowl 47 is located at the rear thereof and with respect to the center gravity of the motor for easier carrying of the motor in transport and in installing the motor on the boat. While maintaining the handle 75 within the normal outlines of the cowl, handle 7S is located so that in transporting, the motor is in balance and can easily be lowered from a dock to the boat.

The weight of the motor is disposed and carried nearer the center of balance or buoyance of the boat which improves the riding qualities of the boat and the propeller thrust and vibration of the engine are transmitted to the transom in directions so that the boat frame supports the loads directly and without wrecking. The forward angularity of the motor provides an improved general appearance which is defined in the greater part by the vertical lines of the motor, and provides the mechanical improvements and advantages as defined and claimed herein.

Various embodiments of the invention may be employed within the scope of the following claims.

I claim:

l. In an outboard motor including a bracket adapted to be secured to the transom of a boat and having an engine including a crankshaft and a crankcase therefor defining at least one crank chamber for receiving a fuel and air mixture for precompression, said crankshaft and crankcase being inclined with the upper end set forwardly respecting the boat; a lower underwater propeller unit having a propeller shaft and outer streamlined dimensions angularly disposed with respect to the motor for normal operation with the motor disposed as supported by the bracket, and a carburetor having control means and a mixing passage open at one end and communicating at the other end with said chamber for supplying the fuel and air mixture thereto, said passage extending in a direction normal to the axis of said crankshaft for the direct delivery of fuel to the crank chamber, and said carburetor being disposed forwardly of the engine where said control means are most accessible to the operator within the boat and said passage is inclined for draining of excess fuel towards and from the lower open end thereof.

2. In an outboard motor, an engine having a crankshaft, a drive shaft connected to the lower end of said crankshaft and in alignment therewith, a hollow drive shaft housing supporting said engine, an underwater gear case fixed to the lower end of said drive shaft housing and journally supporting the lower end of said drive shaft, a propeller shaft disposed horizontally and journally supported within said gear case, said engine crankshaft and drive shaft being disposed on an inclined axis with the upper end thereof disposed substantially forwardly of the lower end, and intermeshing beveled gears carried by said propeller shaft and the lower end of said drive shaft respectively within a chamber formed in said gear case, said gear fixed to said propeller shaft being disposed rearwardly of said other gear and said last named gear being disposed above said propeller shaft and by reason of the angularity of said drive shaft substantially within the minimum contines of said chamber as established by said first named gear.

3. In an outboard motor, an engine having a crankshaft, a drive shaft connected to the lower end of said crankshaft and in alignment therewith, a hollow drive shaft housing supporting said engine, an underwater gear case fixed to the lower end of said drive shaft housing and journally supporting the lower end of said drive shaft, a propeller and a shaft therefor disposed horizontally and journally supported within said gear case, said engine crankshaft and drive shaft being disposed on an inclined axis with the upper end thereof disposed substantially forwardly of the lower end, intermeshing beveled gears carried by said propeller shaft and the lower end of said drive shaft respectively within a chamber formed in said gear case, said gear fixed to said propeller shaft being disposed rearwardly of said other gear and said last named gear being disposed above said propeller shaft and by reason of the angularity of said drive shaft substantially within the minimum confines of said chamber as established by said first named gear, a bracket assembly adapted to be secured to the transom of a boat to support the motor therefrom and comprising a clamp bracket, a swivel bracket pivotally secured to and supported by said clamp bracket for tilting and relative adjustment on a transverse axis, said swivel bracket having bearing means parallel to said drive shaft and adapted to be disposed on an axis parallel to the transom, a bearing turnable on said bearing means and supporting the motor thereon for normal operation, a steering handle for turning the motor on said bearing means to adjust the direction of thrust of the propeller and effect steering of the boat, and resilient means connecting said bracket assembly and said unit to secure the latter in the direction of propeller thrust set by said handle and allowing limited vibrational movement of the unit on said axis parallel to the transom.

4. In an outboard motor unit, an engine having a crankshaft, a drive shaft connected to the lower end of said crankshaft and in alignment therewith, a hollow drive shaft housing supporting said engine, an underwater gear case fixed to the lower end of said drive shaft housing and journally supporting the lower end of said drive shaft, a propeller shaft disposed horizontally and journally supported within said gear case, said engine crankshaft and drive shaft being disposed on an inclined axis with the upper end thereof disposed substantially forwardly of the lower end, intermeshing beveled gears carried by said propeller shaft and the lower end of said drive shaft respectively within a chamber formed in said gear case, said gear fixed to said propeller shaft being disposed rearwardly of said other gear and said last named gear being disposed above said propeller shaft and by reason of the angularity of said drive shaft substantially within the minimum confines of said chamber as established by said first named gear, and a bracket assembly adapted to be secured over the upperedge of a boat transom to support the motor unit with the center of gravity of the unit disposed substantially above the transom and in counterbalance to the thrust of the propeller disposed rearwardly and beneath the transom.

5. In an outboard motor adapted to be secured to the transom of a boat and having an engine including a crankshaft and a crankcase therefor defining at least one crank chamber for receiving a fuel and air mixture for precompression, a limited drain passage from said crank chamber and opening outwardly for discharge of the excess fuel from the chamber, a lower underwater propeller unit having a propeller shaft and outer streamlined dimensions angularly disposed with respect to the motor for normal operation with said crankshaft and crankcase normally inclined and the upper end of the crankshaft set forwardly respecting the boat, and said passage extending from the lower forward region of Said chamber toward which excess fuel tends to collect by reason of such inclination.

6. In an outboard motor adapted to be secured to the transom of a boat and having an engine including a crankshaft and a crankcase therefor defining at least one crank chamber for receiving a fuel and air mixture for precompression, a limited drain passage from said crank chamber opening outwardly for discharge of the excess fuel from within the chamber, said crankshaft and crankcase beingl normally inclined with the upper end set forwardly respecting the boat with said passage extending from the lower forward region of said chamber toward which excess fuel tends to collect by reason of such inclination, and a carburetor having a mixing passage open at one end and communicating at the other end with said chamber for supplying the fuel and air mixture thereto, said mixing passage extending in a direction normal to the axis of said crankshaft for the direct delivery of fuel to the crank chamber, and said carburetor being disposed forwardly of the engine for direct control by the operator within the boat and with said passage inclined for draining of excess fuel towards and from the lower open end thereof.

7. In an outboard motor, a drive shaft, a housing for said drive shaft, an underwater gear case fixed to the lower end of said drive shaft housing and journally supporting the lower end of said drive shaft, a propeller having a shaft normally disposed horizontally and journally supported within said gear case, and anti-cavitation plate extending horizontally over said propeller, said drive shaft being disposed on an inclined axis with the upper end thereof disposed substantially forwardly of the lower end, intermeshing beveled gears carried by said propeller shaft and the lower end of said drive shaft respectively within a chamber formed in said gear case,

and a skeg projecting downwardly from said gear case, the forward leading edge of said gear case and drive shaft housing being inclined forwardly generally parallel to said drive shaft and extending from above said plate and forwardly thereof to said skeg whereby weeds and the like engaged in operation of the motor are passed downwardly and released beneath the skeg.

8L In an outboard motor including a dirigible motor unit having an underwater propeller for normal forward operation, a supporting clamp bracket, a swivel bracket pivotally secured to and supported by said clamp bracket for tilting and relative adjustment on a transverse axis, said swivel bracket having upper and lower resilient means connecting the bracket and motor unit to support the latter, the upper of said resilient means being located forwardly of the lower thereof respecting said normal forward operation and the center of gravity of the motor unit as supported by said resilient means being in a vertical plane passing transversely of the motor unit between said resilient means for the normal support of the unit in the operation of the motor.

9. The invention of claim 8 wherein the dirigibility 0f the unit is on an axis passing adjacent to said resilient supporting means and is accordingly forwardly inclined.

References Cited in the ile of this patent UNITED STATES PATENTS 923,046 Gulick May 25, 1909 1,421,710 Owen July 4, 1922 1,467,641 Johnson Sept. 11, 1922 1,733,361 Rice Oct. 29, 1929 1,932,785 Irgens Oct. 31, 1933 2,096,457 Irgens Oct. 19, 1937 2,204,750 Conover June 18, 1940 2,351,050 Karey .Tune 13, 1944 2,459,594 Smith Ian. 18, 1949 FOREIGN PATENTS 320,915 Italy Sept. 14, 1934 505,852 Great Britain May 17, 1939 

